Determination of Copper and Zinc in Various Beans Samples Followed by Flame Atomic Absorption Spectrometry: A Multivariate Strategy

In the present study, flame atomic absorption spectrometry (FAAS) was used to analyze metal contents (Cu(II) and Zn(II)) in a variety of beans samples. Optimized dry wet acid digestion (DWA) technique was employed to digest all the beans samples. These beans samples were collected during 2014-2015 from the local market of Karachi, Pakistan. Plackett-Burman experimental design (PBD) and 2(3)+star central composite designs (CCD) were used to optimize the DWA method. Parameter influencing such as sample weight (S. wt), acid volume (AV), temperature of the furnace (T) and intensification time in furnace (t) were explored. From these studies, certain variables proved as significant, and were further optimized by a CCD design, which involve 16 experiments. The results obtained by proposed methodology showed sufficiently high % recoveries 98.6 % for Cu(II) and 97.3 % for Zn(II). Under optimized conditions, the detection limits (3 sigma) were evaluated to be 11.2 mu g/Kg for Cu(II) and 5.09 mu g/Kg for Zn(II).